A wave travelling in air falls on a glass plate . It is partly reflected and partly refracted. What is the phase difference between the reflected and refracted waves ?

Options

A. `2pi`
B. `pi`
C. `(pi)/2`
D. zero

Answer

B

Explanation

The wave in air, incident on a glass plate is partly reflected and partly refracted.
For the ray reflected at a denser medium there is a phase change of `pi`. But for refraction from air to glass, there is no phase change .
`:.` There is a phase difference of `pi` between the reflected and refracted waves.